1. Field of the Invention
The present invention relates to a planar microwave line having a dielectric substrate and a planar arrangement of a first microstrip conductor and at least one additional microstrip conductor, in which a gap between the first microstrip conductor and the additional microstrip conductor permits an electromagnetic coupling, to a first region in which the microwave line has a first direction, to a second region, in which the microwave line has a second direction, and to a transition region in which a change from the first direction to the second direction occurs. The invention relates further to a method for guiding a microwave, which propagates in this type of microwave line.
2. Description of the Background Art
This type of microwave line is known from DE 29 43 502, which corresponds to U.S. Pat. No. 4,383,227. This publication relates to suspended microstrip lines, which are therein understood to be a joining of two parallel metal surfaces, a dielectric substrate placed parallel to and between the surfaces, and a first strip-shaped conductor placed on a first surface of the substrate. According to DE 29 43 502, a second strip-shaped conductor is to be placed on the surface of the substrate, the conductor which runs primarily parallel to the first conductor and can be coupled to the conductor electromagnetically. For a curve in the line, this publication stipulates interrupting the first and the second conductor by a slot in a direction of a bisector of the deflection angle and connecting the first and the second conductors crosswise. This should keep the length of both lines equal along the curve. The crosswise connection occurs with the aid of a first connection running within the conductor plane and with the aid of a second connection, which runs outside the conductor plane and is realized in the form of a conducting jumper.
It is also known that discontinuities in the signal path such as open ends, feed-throughs through the dielectric, wave resistance jumps, crossing of lines, or directional changes, for example, breaks in the path of lines, produce distortions in the electromagnetic fields, which corrupts transmitted signals.
For example, coplanar microwave lines without an associated ground plane on a substrate side, which is opposite to the substrate side with the planar microstrip lines, with straight routing exhibit very good high-frequency properties. With directional changes, as occur, for example, in a routing in arcs, on the contrary, undesirable signal corruptions and shifts in the electrical ground-zero point occur.
The prior-art microwave line with the interruptions and the conducting jumper extending from the plane into the third dimension also exhibits discontinuities and thereby undesirable wave resistance increases.